Wow! I hope I look that good when I am 201.
The musket most used by the Americans in the early part of the Revoluionary War was the .75 caliber English "Brown Bess", which the British had provided to colonial militias. Later, as arms came from France, the .69 Model 1768 (Charleville) became the effective standard.
It was the latter musket that the new nation copied and produced for its own use at Springfield Armory, starting in 1795. The Model 1795 was the first regulation service arm produced entirely in a national armory and is historically very important as it was the start of volume arms production in the United States.
The Armory at Springfield, Massachusetts was completed in 1795; production of muskets began almost immediately, and continued until 1814. Greatest volume production was in 1811, when 12,020 were made, of a total production of 96,000. (An additional 70,000 were made at Harpers Ferry, VA, 1800-1815.)
Collectors classify those muskets by type, based on variations; that is a Type III.
It is hard to make a realistic value assessment, but I would guess at around $8000, but it could go higher. Those muskets, complete and relatively intact, just aren't seen too often outside museums.